Knitting machines



April 1965 A. H. CROUCHER 3,177,686

KNITTING MACHINES Filed Aug. 13, 1962 2 Sheets-Sheet l April 13, 1965 A. H. CROUCHER 3,177,686

KNITTING MACHINES Filed Aug. 13, 1962 2 Sheets-Sheet 2 United States Patent 3,177,686 KNITTING MACHINES Antony Harry Croucher, Esher, England, assignor to Wildt Meilor Bromley, Limited, Leicester, England Filed Aug. 13, 1962, Ser. No. 216,573

Claims priority, application Great Britain, Aug. 18, 1961,

3 Claims. (Cl. 66-8) This invention relates to knitting machines.

Knitting machines currently available are generally of an extremely complicated nature as the needles have up to five selectable operative positions and the setting up of the machine for a particular pattern is time consuming. This complication arises largely from the use of purely mechanical actuation and control of the needles. It has been proposed to control the needles electronically but the utilization of electrical signals to produce forces large enough to provide the needle accelerations necessary for normal operation of the machine entails great complication.

According to the invention the needles are actuated by fluid pressure, preferably hydraulically.

Thus a relatively small force may actuate a valve to admit fluid pressure to a working chamber to actuate each needle. The various positions of the needle may be selected by using a stepwise operable actuating mechanism for each needle in conjunction with a source of variable fluid pressure, preferably also operable in stepwise manner so that the increments of fluid pressure are suflicient to operate the steps of the actuating mechanism in a rapid action.

One convenient form of the pres-sure source includes a multi-position valve operable progressively and selectively by suitable control means such as a cam, to interconnect at working chamber selectively with exhaust and a series of stepped input hydraulic pressures.

Thus in a released position, the valve connects the working chamber with exhaust. A first stage of operation closes the connect-ion to exhaust and opens one to a first pressure source. Further operation closes the connection to the first pressure source and opens one to a second, higher pressure, pressure source, and so forth.

The pressure source and actuating mechanism are preferably combined so that the working chamber of the pressure source is partially defined by a plunger of the actuating device.

A convenient form of the actuating mechanism includes an operating plunger partly defining the working chamber. The plunger carries a push rod for operating the needle, and slidably located in a housing are a series of sleeves coaxial with the push rod and through which the push rod is slidable. The end of the plunger remote from the working chamber and the ends of the successive sleeves are exposed to control pressures in ascending order of magnitude, and the plunger movement is arranged successively to entrain the sleeves against the action of associated control pressures, with each sleeve abutting the succeeding sleeve until the control pressure force exceeds the actuating pressure force on the plunger and push rod to complete their travel.

The use of hydraulic control pressures ensures a rapid return of the plunger and sleeves, and the use of a stepped pressure source ensures a rapid action if the successive pressures are chosen so that the successive control pressure forces are overcome by a sufficient margin.

The invention will be further described with reference to the accompanying drawings of a preferred embodiment of the invention, and wherein:

FIGURE 1 is a section on the line 1-1 of FIGURE 3 through a ring of needles of a circular knitting machine, only one needle being shown together with its actuating "Ice and control devices, the hydraulic fluid circulating arrangements being illustrated diagrammatically;

FIGURE 2 is a section on the line I I--'II of FIGURE 3 showing only a single needle in a different operating position;

'FIGURE 3 is a partial section of the machine taken on the line IIIII-I of FIGURE 1; and

'FIGURE 4 is a section on the line IV-lV of FIG- URE 1.

FIGURES 1 and 2 each show one needle 11 of a circular knitting machine. The needle itself and the knitting arrangements are of a generally conventional type and will not be described in detail. The needles are pivotaJble about axes 12 between a position 1, shown in full lines in FIGURE 2 and phantom in FIGURE 1, and a position 5, shown in phantom in FIGURE 2 and full lines in FIGURE 1. in the position 1 the needle 11 is restingagainst an abutment surface 13 formed on a stitch length control device 14 threaded on the machine body at 15, and of which the position is adjustable by rotation of a gear .16 (shown in FIGURE 2). The gear 16 is formed with screw driver slots for manual operation.

In the position 1 the needle is in position for the loop forming operation, in intermediate positions 2, 3 and 4 illustrated it is set for miss, tuck and clear respectively, and in the extreme position 5 for transfer.

FIGURE 2 also shows a loop transfer needle 1 1a.

For clarity of illustration only one needle and associated actuating mechanism has been shown in each of FIGURES 1 and 2, but the partial section of FIGURE 3 gives some idea of the arrangement of the needles around the machine.

The needles are each actuated by a vertically reciprocable link 17 connected to a yoke 13 on the needle 11. The link 17 is solid with a push rod 19 itself solid with a plunger 21. The push rod 19 passes through a series of sleeves 22, 23, 24, and the pressure on the plunger 21 is controlled by a reciprocable valve sleeve 25. The upper ends of the plunger 21 and the sleeves 22, 23 and 24 are domed or cham-fered as shown. The valve sleeve 25, sleeves 22, 23, 24, the plunger 21, the push rod 19 and the link 17 are all reciprocable in aligned bores of the body parts. The bore so formed communicates with a series of annular chambers formed in the body, the chambers being denoted by references 26, 27, 28, 29, 39, 31, 32, 33, 34, 35 and 36.

The lower end of the bore is closed by a plug 37 having a stop 38 for the plunger 21, and held in position by pin 33, also acting as a limit stop for the valve 25.

FIGURE 1 shows diagrammatically the arrangements for supplying pressurised oil to the annular chambers. A group of eight oil pumps 40 are arranged to pressurise lines leading to the chambers 27 to 30 and 32 to 35. The

pumps are driven by a motor 41 and are located in an oil reservoir42 with which the chambers 26, 31 and 36 are connected by lines so as to provide effective venting of the chambers and a return path for oil leaking along the bores in the body past the plungers, sleeves and so forth. Each oil pump is associated with a pressure control valve 43 returning excess delivery to the reservoir and maintaining the pressures in the annular chambers 27 to 3lland 32 to 35 at fixed pressures in ascending orders of mag nitude within each group.

As an example, for the relative proportions of the sleeves and effective pressure area of the plunger 21illusstrated in FIGURES 1 and 2, the pressure in the chamfit in the sleeves 22, 23 and 24 and it will be noted. each,

or to admit pressurised fluid from one of the chambers,

and the valve is selectively operable to five positions numbered on the drawings to correspond with the resulting positions of the needle with the addition of primes, into which it is movable by a sequence/ pattern controller.

The operation is as follows. In the position ll adopted by the valve 25 in FIGURE 2, the interior of the sleeve valve below the plunger 21, which forms a Working chamber 45, is exhausted and the plunger is pressed downward- 1y by the pressure in chamber 32 acting on its upper end until the needle adopts the position 1 abutting the stitch length controller 14.

Movement of the valve 25 into position 2 pressurises the working chamber 4-5 with the pressure in chamber 27, i.e. at a first pressure level. This pressure is sufiicient to overcome the pressure in chamber 32 so that the plunger moves upwardly until its end abuts sleeve 24. The upward pressure force is insuflicient to overcome the downward pressure force on the sleeve 24 exerted by the fluid in the chamber 33 so that the plunger movement stops. This movement is transmitted to the needle by the push rod so that the needle takes up the position 2, which is thus clearly defined by the position of the sleeve 24.

When the valve is moved to the position 3, pressurised fluid from chamber, 23 is admitted to the working chamber 45 and this increased pressure is sufficient to move the plunger so as to move the sleeve 24 up to the sleeve 23, but not to move the sleeve 23 against the pressure in the chamber 34. The effective area of sleeve 23 being larger than the effective area of plunger 21, the lower pressure in chamber 34 can resist the pressure in the working chamber adequately.

The operation for positions 4 and 5 is similar. When moving into these positions, the heads of sleeves 24 and '23 enter the bores for sleeves 23 and 22. The position 5 ofthe needle is defined by a' stop 44 for the sleeve 22 as is shown in FIGURE 1.

The pressures in the chambers 27 to 30 are such as to overcome easily the downward pressure and friction forces involved so that the. action of the needle is rapid.

For movementin the reverse direction the domed or chamfered upper ends of the sleeves and plunger allows them to part them successively from the stop or next upper sleeve to cut off the downward pressure forces on the plunger successively. Exit of the heads of sleeves 23 and 24 from the bores brings into play additional smaller downward pressure forces to replace those cut oil.

These downwardrforces are also sufiicient to overcome easily the upward forces involved in the successive stages so that rapid action is achieved.

Various modifications may be made within the scope of the invention. Thus theneedles may be operated by pneumatic pressure. Also either or both of the pressure source and actuating mechanism may be replaced by alternative forms.

I claim: 7 a L In a knitting machine comprising a plurality of needles each having a series of operating positions; an individual stepwise operable fluid pressure operated means for actuating each needle to the said series of operating positions, a housing, a series of chambers in said housing, a source of fluid pressure simultaneously providing stepped fluid pressure to the said chambers, a further chamber in the housing being connected to an exhaust, a multi-position valve for each of the needles actuating means being arranged in one position to connect the actuating means. with said further chamber and in further positions to connect the actuating means selectively with the said series of chambers, and control means for positioning the multi-position valve.

2. In a knitting machine comprising a plurality of needles each having a series of operating positions, a housing, a variable source of fluid pressure, an individual stepwise operable fluid pressure operated mechanism in' the housing for actuating each of the needles to the said operating positions and control valve means for controling the application of fluid pressure from the said source to the actuating mechanism, each actuatingmechanism comprising an operating plunger partly defining a working chamber and carrying a push rod for operating the needle, a series of sleeves slidably located in the housing and coaxial with the push rod, the push rod being slidable in the sleeves, a series of pressure chambers in the housing being arranged to expose the end of the plunger remote from the working chamber and the ends of successive sleeve to control pressures in ascending order of magnitude, the movement of the plunger being adapted to entrain the sleeves successively in its movement against the action of the associated control pressures until the control pressure force exceeds the actuating pressure force on the plunger and push rod.

3. In a knitting machine comprising a plurality of needles each having a series of operating positions; a

housing, a first series of chambers in said housing, one

of said chambers of said first seriesbeing connected to exhaust, a source of fluid pressure simultaneously providing stepped fluid pressures to further chambers of said first series, an operating plunger for each of the needles reciprocable in the housing and partially defining a working chamber in the housing, a push rod for operating the needle being carried by each plunger, a multi-position valve for each plunger being reciprocable in the housing and being arranged to connect the working chamber selectively to the chambers of the said first series, a series of sleeves reciprocable in the housing and coaxial with each push rod, the push rod being slidable in the sleeves, a

second series of chambers in the housing being arranged to be pressurized with stepped control pressures, one end of each sleeve of the said series of sleeves being exposed to control pressure in a respective chamber of said second series, the movement of the plunger being adapted to entrain the sleeves successively in its movement against the action of the associated control pressures until the 'control pressure force exceeds the actuating pressure force on the plunger and push rod. 7

References Cited by the Examiner UNITED STATES PATENTS RUSSELL c. MADER, Primal Examiner.

DONALD W. PARKER, Examiner.

11/40 Ford 66-9 2 

1. IN A KNITTING MACHINE COMPRISING A PLURALITY OF NEEDLES EACH HAVING A SERIES OF OPERATING POSITIONS; AN INDIVIDUAL STEPWISE OPERABLE FLUID PRESSURE OPERATED MEANS FOR ACTUATING EACH NEEDLE TO THE SAID SERIES OF OPERATING POSITIONS, A HOUSING, A SERIES OF CHAMBERS OF OPERATING ING, A SOURCE OF FLUID PRESSURE SIMULTANEOUSLY PROVIDING STEEPED FLUID PRESSURE THE SAID CHAMBERS, A FURTHER CHAMBER IN THE HOUSING BEING CONNECTED TO AN EXHAUST, A MULTI-POSITION VALVE FOR EACH OF THE NEEDLES ACTUATING MEANS BEING ARRANGED IN ONE POSITION TO CONNECT THE ACTUATING MEANS WITH SAID FURTHER CHAMBER AND IN FURTHER 